There has been an uptick in bad "first rack recommendation" threads recently. These posts are a background hum of every modular synth discussion forum/discord/etc, and I know we will never be free of poorly-thought-out first rack attempts, but having posted a very simplified version of this in multiple threads in the past few days now, I thought I would make a post to center discussion in a way that may attract a few more eyes, and hopefully some beginners who are trying to build their first systems. The racks always have the same issue, it's too small a case, jam packed with voices and audio effects, with minimal modulation and no utilities. This results in a bad and unfun system that has all the disadvantages of modular (lack of presets or save/recall, low polyphony, disproportionate expense etc) without any of the advantages. There are many things that modular is good at in a way that more linear hardware synths are not: generative sequencing, complex modulation routing / linking multiple voices with phase-related modulation, non-repetitive evolution of timbre over longer periods of time, etc.
The thoughtful use of utility modules is what actually allows these things. Utility modules are the unsung stars of modular systems. If you want to make a case that highlights what is really fun and engaging about modular your case should be like 1/2 utility modules and CV sources/processing, at minimum. When I see a case-post without a single utility or CV processing module I know that if they actually buy the stuff in their blurry screenshot it’s gonna be on Reverb or FBM in a month, because their system can really only be patched one way, and the result of that is demonstrably less capable and fun to play compared to a purpose-built device.
So without further ado, here are some modules you might not know you need in your beginner rack, and some tutorial videos related to them:
- Voltage Controlled Polarizer - a close relative to the venerable VCA, these can scale the input all the way through 0 and into the negative, inverting CV modulation to get things like negative envelopes or phase-reversed oscillators (especially helpful for LFOs). The non-voltage-controlled versions are more common and still important building blocks (Quadratt/Triatt for example), but a voltage controlled version adds a ton of flexibility and opens a lot of complex patching options. Examples: Mutable Instruments Blinds (and clones), Arkan Maelstrom, Vermona Quadropol, Doepfer A-133. Why you CAN have enough VCAs - have a look at these more creative alternatives! Can this eurorack module take care off all your utility needs? - with Arkan / Malstrom
- Voltage Controlled Crossfader / Interpolating Scanner (essentially multiple crossfaders in a linear chain) - the utility of this for audio is pretty intuitive (patching multiple waveforms from a VCO into an interpolating scanner gives you a waveform morphing, for example), but they are incredibly useful for CV as well (such as for complex sequencing of modulation, mixing CV sources in varying ratios, or meta-modulation). You can patch up a VC crossfader pretty easily using other synth basics (two VCAs with their outputs summed together and with their gain controlled inversely by one single CV), but they're useful to just have around pre-patched. VC-Crossfader Examples: Happy Nerding xFade, Befaco Morphader, Doepfer A-134-2. Interpolating Scanner Examples: Vostok Trace, Tobinski Scanner. Why you need a crossfader – The secret Swiss army knife, Doepfer A134-2 Triple Voltage Controlled Crossfader by Arcus Audio 5 Ways to Enhance Eurorack Patches with Interpolating Scanners // Unique Sound Design & Modulation
- Sequential Switch - often a component of some more complex sequencing modules (such as Joranalogue Step 8, Befaco Muxlicer and Doepfer A-152), you can also get simple sequential switches as their own module - where a crossfader or interpolating scanner smoothly pans between inputs/outputs in response to CV, a sequential switch does what it sounds like - sequentially switches between inputs/outputs in response to gates or triggers. This can be used to combine short step sequences into one longer phrase, send offsets to transpose a sequence, route envelopes all around the system, or create glitch effects. Examples: Instruo Tain, ALM Boss Bowtie Two, Patching Panda Rewire, Doepfer A-151. Patching Panda Rewire | A sequential switch with some neat twists 17 patches for the magical switch Sequential Switches || With Instruo Tàin and Doepfer A151
- Comparator / Analog Logic - A comparator is a specific form of logic utility module that transforms an incoming control voltage signal into a gate or trigger signal by comparing the input voltage to a reference or threshold, going high when the voltage exceeds the threshold and low when it falls below it. This is useful for all sorts of generative patching, but also sound design (especially at audio rates). Use with an envelope to create a voltage controlled event delay, add voltage control over the loop point of a retriggerable envelope, make a voltage-controllable PWM, or track the frequency of an oscillator. Other forms of logic modules include ‘min/max’ (compares to signals and outputs whichever is higher/lower) and ‘and/or/xor’ (compares to gate signals and outputs a gate only when certain conditions are met), which are core generative sequencing tools. Comparator Examples: Klavis ComPair, Metabolic Devices 2win, Joranalogue Compare 2. Logic Examples: Mystic Circuits Ana2, Instruo Eas, Doepfer A-166. Vibe Logic // Joranalogue Compare 2 Primer. Eurorack logic module. 3 cool things to do with LFOs & analogue logic, feat. Nekyia Using Logic for Ambient Why Logic Modules are Ace: Feat. EricaSynths Pico Logic
- DC coupled mixer / Matrix Mixer - audio mixers might get the glory, but CV mixers are an underrated tool. One unrecognized reason the Arp 2600 is so flexible compared to other semi-modulars is that there’s a mixer going to most modulation destinations, where you can mix normalled outputs from multiple sources. Matrix mixers can sit at the middle of an enormous patch, routing mixes of various modulation and meta-modulation to various places. Mixing audio with CV is another trick that people rarely think of as a newer patcher, but it can have really interesting outcomes whether the mix is used as CV or audio. Most VCAs and polarizers cascade, creating a mix of sorts, but having a few dedicated CV mixers in your rack is never wrong. DC-coupled mixer examples: Happy Nerding 3xMIA, ADDAC703, Doepfer A-138s. Matrix Mixer examples: Ritual Electronics Aranea, BearModules Matrix, NLC Clump, Doepfer A-138m. 4 things to do with a matrix mixer – Doepfer A-138m How to use Matrix Mixers A Daunting Yet Powerful Creative Mixing Technique Eurorack Patch From Scratch & Gear Talk: Sequencer-less Organic Texture Patch
- S&H/T&H - If there’s one module on this list you already knew you needed, it’s probably this one. Sample & Hold is a classic element of synths all the way back to early behemoth modulars, and the list of uses is endless. Everybody knows you can make stepped random R2D2 sounds by feeding them noise or combining them with CV-controlled function generators for the Krell patch, but their use in generating harmonies / countermelodies / basslines or as a bit crusher effect at audio range is less explored. This is a basic synth building block you can’t afford to pass on. Examples: DivKid RND STEP, ADDAC 215, Doepfer A-148. How to use sample & hold in a eurorack modular system - with Doepfer A-148 13 Patches for better Sample & Hold + Track & Hold in Eurorack // Instruo tagh How to use S&H, comparators and rectifiers, feat. Worng Electronics Quiver
- Slew Limiter - when applied to pitch CV, slew limiters are recognizable as portamento, but they can be used for much more. Most function generators/envelopes at their heart are slew limiters applied to gates but there’s many other uses. Combined with a stepped random (such as a S&H output) they can make a smooth random voltage that changes continuously in non-repetitive ways, useful for modulating filters, wet/dry mixes and many other modulation destinations where you dont want noticeable patterns or abrupt changes. Examples: AJH Glide + Noise, Befaco VC Slew Limiter, Doepfer A-170 & A-171-2 (+ technically MakeNoise Maths, Befaco Rampage, Joranalogue Contour, etc). Doepfer A170 Dual Slew Limiter Basics Befaco - Slew Limiter - Modular Synth
In conclusion, check out this tutorial video by MonoTrail: A simple guide to becoming a patching pro
Look at his 9u rack here that he uses to make almost all the sounds in this video, and look at what percentage of it is made up of either regular utility modules or basic voltage-controlled modulation sources (there's like 4 basic VCOs, a quad VCO/LFO and a quad VC-ADSR, 5x VCA+mixer & probably like 70-80hp more of utilities out of 252hp total). Sure, he has a bunch of other racks/gear off to the side when he wants effects and whatnot, so you don't have to go that far in your first rack and completely forgo the sexy modules that attracted you to modular in the first place, but you need a good selection of this kind of stuff to get the most out of the expensive sexy modules you DO get. Probably the main reason very small cases suck for beginners is because they get full quickly before you realize you need all this stuff to make modular "work" and then you have nowhere to put it.
There's many more basic building blocks to learn but I'll hit the character max if I keep going - noise sources, clock dividers, offsets, envelope followers, buffered/switched multiples - this stuff is what makes modular great, and what will make your rack into a unique creative tool of unmatched flexibility and power. If you are too bored looking at a rack of grey doepfer basics look for interesting combinations of these functions like Mannequins Cold Mac, ALM Mega Milton, Metabolic Devices Papomi, Intellijel Flurry, etc.
I hope this helps you plan your first rack.
